A hydrocyclone is a device that applies centrifugal force to a mixed fluid to create controlled vortex flow patterns in order to classify, separate or sort particles in the mixed fluid based on the sizes or densities of the particles. Additionally, a hydrocyclone may be used to separate solids from liquids or to separate liquids of different density or viscosity.
A hydrocyclone will normally have a cylindrically shaped primary housing at the top where the mixed fluid is being fed tangentially, and a conical base. With the controlled vortex flow patterns, heavy components move outward toward the wall of the cylinder where they agglomerate and spiral down the wall to an outlet at the bottom of the conical base. Conversely, light components move toward the axis of the hydrocyclone where they move up toward an outlet at the top of the device. Generally, hydrocyclones are used in continuous flow systems so that the instantaneous liquid inflow to the hydrocyclone is equal to the total instantaneous outflow of the light components plus the heavy components.
Existing hydrocyclones are passive devices, e.g. simply introducing the mixed fluid tangentially to the cylindrical section generates the circular and then the vortex flow patterns. Unfortunately, in these existing hydrocyclones, the mixed fluid being fed into the primary housing must be within certain parameters of fluid pressure and flow velocity. For example, if either the flow rate or pressure is below certain lower limits, the initial circular flow fluid in the primary housing is not generated and the fluid in effect slides down the conical base and out of the outlet at the bottom of the conical base without separating the different weight components. Additionally, if either the flow rate or pressure is above certain upper limits, the entering fluid immediately becomes chaotic and the circular pattern in the primary housing is never established and the different weight components can not be separated efficiently and effectively. Therefore, in these existing hydrocyclones, the operating range of fluid pressure and velocity has to be met and maintained in order for the vortex pattern to be created and operate.